1. Field of the Invention
The present invention relates to operational amplifier circuits, and particularly to a current-feedback operational amplifier-based sinusoidal oscillator.
2. Description of the Related Art
In the recent past, a number of sinusoidal oscillator circuits exploiting to advantage the parasitic of a single current-feedback operational amplifier (CFOA) have been proposed. The minimum number of CFOAs used is one, and the minimum number of externally connected passive components used, so far, is two. However, the circuit reported in the prior art uses a grounded capacitor and a floating resistor, and assumes that the CFOA is modeled by a two-pole model. The first pole is the open-loop dominant pole and results from the internal compensation capacitor at a terminal of the CFOA. The second pole results from the current mirrors of the CFOA. Typically, the current mirror pole frequency is much higher than the pole frequency due to the transimpedance of the CFOA. This fact should be exploited to economize on component count.
Thus, a current-feedback operational amplifier-based sinusoidal oscillator solving the aforementioned problems is desired.